Concerned by the growing use of doping agents in sports, the European Commission has decided to support a consortium of nine groups of researchers from six European countries with the aim of developing a definite tool (a highly-sensitive analytical test) for the detection of illegal drugs. Current analysis techniques are not sensitive enough to detect banned substances at very low concentrations. The Isotrace project aims to remedy this situation by improving the detection limit of an analytical technique called isotope ratio mass spectroscopy (IRMS). Carbon isotopes are different forms of carbon atoms that differ only in their weight. This IRMS method is an extension of a well-established mass spectroscopy technique, which is basically a specialised weighing machine. IRMS can thus determine the relative ratio of isotopes in a sample.

Natural carbon is composed of three isotopes: Carbon-12 making up about 98.9%; Carbon-13 about 1.1%; and Carbon-14 in a negligible amount. Measurement of the carbon-13 to carbon-12 ratio permits the recognition of carbon compounds from a variety of different sources. Those molecules produced biologically, that is, naturally in the body, will have a well-established ratio, which is determined by the carbon-isotope ratio of what (food) has been consumed. This ratio will be different in exactly the same molecules made non-biologically, that is, synthetically in the laboratory. It can be used therefore to discriminate between two chemically identical molecules from different sources. Natural hormones made by the body can be differentiated from those made synthetically by laboratory chemists. Current analysis techniques can detect substances in urine samples in low concentrations but a sensitivity of at least ten times greater is needed.

"Any improvement in the sensitivity of the technique will come from improvements in all of the steps in the IRMS testing process, from the separation of the sample into its component parts, to the conversion of these components into new compounds suitable for analysis and purification," according to Rainer Stephany of the Laboratory for Residue-analysis in the Netherlands.

"Other improvements will include the extension of the IRMS technique to isotopes other than those of carbon, in particular the use of hydrogen isotopes for detecting banned substances and thus its potential as an indicator of drug-abuse," he says.

The team has already been working together for more than a year and is, according to Tom Preston (a professor of Biochemistry at Scottish Universities Environmental Research Centre, one of the institutions involved in the project) already close to the "halfway" mark. "We are having a mid-project meeting towards the end of 2001, and at this stage we should have achieved an increase in sensitivity for the measurement of carbon-13 content in biological samples," he says.

The consortium includes scientists with experience in both human and animal drug testing and in instrumentation. The team, which is lead by Professor Jordi Segura of the Department of Pharmacology and Toxicology at the Institut Municipal d'investigacio Medica (IMIM) in Barcelona, Spain, includes scientists from eight institutions in six countries. They include Trinity College in Ireland, the Scottish Universities Research and Reactor Centre and the manufacturer PDZ Europa in the United Kingdom, the CNRS-Service Central d'Analyse in France, the Doping Control Laboratory in Greece, the Laboratory for Residue-Analysis in the Netherlands and, of course, the IMIM.

The resulting technology will be patented and manufactured in Europe for export all over the world. "A major focus of the programme is to have the new test ready for use in the Olympic Games in Athens in 2004," explains Preston. If this can be done, the project will further enhance the reputation of EU laboratories as leading technological innovators in the fight against drug abuse in sport.